Genetic variants and device upgrade in young pacemaker recipients
J M Sanchez Moreno, J G Soto Rojas, I Garcia Olea, J A Becerra Gajon, A Bonilla Lopez, J M Garcia Torrecillas, M Anton Aranzana, J Aceituno Cubero, F J Tornes Barzaga, R Fajardo Molina, C Gomez NavarroAbstract
Background/Introduction
Early-onset rhythm disturbances such as advanced atrioventricular block or symptomatic severe sinus node dysfunction are uncommon in young adults and may be associated with pathogenic genetic variants. Some patients subsequently require device upgrade to defibrillator or resynchronisation therapies.
Purpose
To compare patients with and without structural heart disease at the time of pacemaker implantation and to assess the impact of genetic testing on clinical follow-up and upgrade indications.
Methods
We conducted a retrospective observational study of patients younger than 60 years who underwent pacemaker implantation for advanced atrioventricular block or severe sinus node dysfunction, excluding reversible causes, in two tertiary centres from 2015 to January 2025. Genetic testing was incorporated into aetiological evaluation from 2021. Patients were grouped according to the presence or absence of structural heart disease (left ventricular wall thickness greater than 15 mm and/or ejection fraction below 45%). Demographic, echocardiographic and device-related outcomes were analysed.
Results
Twenty-two patients were included (Group A n=17 without structural disease; Group B n=6 with structural disease). Group A was younger (43.7 versus 51.8 years, p<0.05). Pathogenic variants were identified in 47% of Group A (mainly LMNA, EMD and DSP) and in 83.3% of Group B (predominantly PRKAG2, LMNA and MYH7). Physiological pacing was implanted in 15% versus 33.3% of patients respectively. During follow-up, device upgrade to implantable cardioverter-defibrillator or resynchronisation therapy occurred in 29.4% of Group A and 33.3% of Group B. Genetic findings prompted upgrade in 62.5% of cases, whereas 37.5% were upgraded due to ventricular tachycardia or progression of cardiomyopathy. Ventricular tachycardia occurred in 11.8% versus 50% of patients in Groups A and B respectively, without statistically significant differences.
Conclusion(s)
Young patients requiring pacemaker implantation, with or without structural heart disease, show a high prevalence of pathogenic variants. The need for device upgrade is considerable in both groups. Genetic testing is essential for risk stratification and long-term management in this population.Baseline characteristics